Hokkaido-Akita Cable

Overview

The Hokkaido-Akita Cable is a domestic submarine cable system connecting two landing points within Japan. Spanning 770 km, it serves an intra-Japan corridor linking the island of Hokkaido with Honshu via the Sea of Japan coast. The cable has been in service since 2023 and is jointly owned by four of Japan's principal telecommunications operators.

Route and Landings

Both landing points are located in Japan. The cable connects Sapporo, on the island of Hokkaido, with Akita, situated on the northwestern coast of Honshu. At 770 km, the route spans the waters between these two cities without touching any other country.

Ownership and Operators

The Hokkaido-Akita Cable is jointly owned by KDDI, NTT, Rakuten, and SoftBank. These four companies collectively represent a broad cross-section of Japan's domestic and international telecommunications market, with KDDI and NTT among the country's longest-established carriers and Rakuten and SoftBank representing newer entrants to mobile and broadband infrastructure.

Status and Timeline

The cable became ready for service in 2023 and has been operational for approximately three years. It is among the more recently commissioned submarine systems serving Japan's domestic network.

Regional Context

Japan is served by 38 submarine cables landing across 46 landing points, with an average cable length of around 6,374 km — reflecting the country's role as a terminus for many long-haul trans-Pacific and intra-Asian systems. At 770 km, the Hokkaido-Akita Cable is shorter than most cables sharing the same national footprint, falling longer than only 24% of the 33 other cables touching Japan. Its regional peers in Japanese waters include far longer international systems such as EAC-C2C (36,500 km, RFS 2002), APCN-2 (19,000 km, RFS 2001), and JUPITER (14,557 km, RFS 2020). The Hokkaido-Akita Cable is distinct from these in that it serves a purely domestic purpose rather than connecting Japan to other countries.

Strategic Role

By connecting Sapporo on Hokkaido directly to Akita on Honshu, this cable provides a dedicated submarine link between Japan's northernmost major island and the mainland. The involvement of all four major Japanese telecoms operators reflects a shared interest in building resilient domestic connectivity for Hokkaido, a region that has historically depended on a more limited number of terrestrial and submarine pathways to the rest of the country.